On a Charge

Electric vehicle charging is in something of a muddle, with two different types of connectors in Europe, some cars that can be fast charged and some that cannot, while the US 110v grid poses its own unique issues. There is an agreement to work towards a standardised set of plugs and connectors and communication software in Europe. That would be a welcome step forward.

Another possibility is gaining support too. There’s nothing particularly new about inductive charging. Just about everyone who uses an electric toothbrush will be familiar with the technology, with no direct electrical contact between brush and power point.

Induction is also vital to the workings of the electric motor. Inductive charging has been used on electric vehicles in the past. General Motors’ ill-fated EV1 from the 1990s used the technology to recharge the car’s batteries, by inserting an inductive “paddle” into a slot between the car’s headlamps.

Ground Effect

The focus is slightly different now and centres on fitting a charging pad to the ground, or embedding it under the road surface. A similar pad is fitted to the car, then all the driver has to do is park over the pad – with the help of a guidance system and activate the charging. There is no need to plug in to a charging point.

Qualcomm is developing the technology with a view to licensing it to vehicle manufacturers and EV equipment suppliers and is trying to standardise the technology as far as possible. A ground pad is around 600mm by 600mm and between 20mm and 30mm deep.

Adaptable technology

Anthony Thomson, vice president of business development at Qualcomm Europe Inc, says the company is following the European charging systems for plug-in charging and will offer a 3.3kW standard charger, 6.6kW fast charger and 20kW rapid charging system. The pad fitted to the vehicle would vary in size according to the charging system used. For the 3.3kW system the vehicle pad would be around 250mm x 250mm x 18mm. For vehicles with higher ground clearance, it might be necessary to make the pad a bit bigger. It would be bigger still for a 6.6kW charger – approx. 480mm x 300mm. The two systems could be combined in one pad, but another larger pad would be needed for 20kW charging.

Guidance system

Lining the car up over the pad is quite critical and Qualcomm, working with vehicle manufacturers, has come up with a circular dashboard display with a smaller circle at the centre.

'As the circles around the segment fill up,' explains Anthony Thomson, 'they change from red to amber to green, so you can see where you are very quickly at a glance.

'Once you reach green, there’s an audible tone to indicate the vehicle is lined up.'

Qualcomm has been working towards three different types of ground pad. One is surface mounted, which would be comparatively simple for fitting to a driveway, garage, car port or business car park. For heavier-duty applications, such as a supermarket delivery vehicle fleet, either a flush fitting or a covered pad is preferred to reduce the possibility of damage. In the short term, Qualcomm expects both induction and plug-in charging systems to be fitted to vehicles. But that could change.

'I think we’re focused on the premium segment with EVs and plug-in hybrids at the moment,' says Thomson. 'Talking to us, those manufacturers are using phrases like "This is just going nowhere with the plug" and "There won’t be a plug in five years, it will have to be wireless." That’s a huge shift from when I started talking to these guys five years ago. There was a real suspicion over whether wireless charging was possible.

'Then it shifted to "How efficient is it?" Then to "How safe is it?" Now we’re talking about "What’s the cost?"'